1. Field of the Invention
The present invention relates to an antibacterial colorant and a composition containing the same. More particularly, the invention relates to an antibacterial colorant achieved by combining an antibacterial agent with a dye or a pigment and a composition containing the same.
2. Description of the Related Art
Generally, colorants are substances that develop their colors by selectively absorbing or reflecting visible light. Colorants are widely used in a variety of coloration industries, for example, in foods, drugs, cosmetics, paints, ink-jet inks, toners, fibers, leathers, plastics coloration, rubbers coloration, furniture fabrication, textile printing, paper-making, and ceramics. There are two types of colorants: dyes and pigments. Dyes are colored substances that are dissolved and mono-dispersed in water or oil and are bonded to molecules of substrates, such as fibers, for coloration. Pigments are not dissolved in water or oil, and thus, pigment powders form opaque colored films on the surfaces of substrates. Conventionally, dyes provide a wide color gamut and a bright and clear color. However, decoloration or discoloration by light and running of colors in water or organic solvents are likely to occur. Therefore, dyes have poor light and water resistance. On the other hand, pigments have better light and water resistance than dyes. However, when pigments are exposed to ultraviolet light from the sun or the like for an extended period of time, the pigments may become decolored. In addition, pigments provide a narrower color gamut and types of pigments are not diversified, relative to dyes.
An ink composition containing dye or pigment faces another problem when bacteria are generated in ink, deteriorating the quality of ink and storage stability. For these reasons, antibacterial agents are separately added to compositions containing colorants in an attempt to avoid the generation and growth of bacteria. However, such antibacterial agents lower the stability of the compositions, thus generating precipitates. Therefore, it is difficult to ensure consistencies of the compositions. In addition, when the compositions are projected onto substrates through small-sized orifices, in particular, as in ink-jet printing, the orifices are easily clogged due to coagulation of the compositions.